Many machines use engines to produce power for performing various tasks. Engines often produce power by delivering fuel and air to a combustion chamber and combusting the fuel with the air to drive a working member of the engine, such as a piston. Many factors affect whether and how completely the fuel combusts with the air in the combustion chamber. For example, temperatures in the combustion chamber and the manner in which fuel is delivered to the combustion chamber may affect whether combustion occurs successfully in the combustion chamber. Accordingly, many engines have engine controls that are configured to promote successful combustion by controlling fuel delivery to the combustion chamber dependent upon inputs from an engine temperature sensor, such as a coolant temperature sensor. However, in some circumstances, the signal from an engine temperature sensor alone may not be a good indication of temperatures in the combustion chamber of an engine.
U.S. Pat. No. 5,231,962 to Osuka et al. (“the '962 patent”) discloses an engine that controls fuel delivery into the combustion chambers dependent upon air temperature and engine coolant temperature. The '962 patent discloses a diesel engine having a fuel injection control system with a controller that controls fuel injection into the combustion chambers. The '962 patent discloses that the fuel injection control system operates either in a “normal fuel injection mode” or a “split fuel injection mode.” In the “normal fuel injection mode,” the fuel injection control system causes a single, continuous fuel injection into each combustion chamber during each power cycle. In the “split fuel injection mode,” the fuel injection control system causes multiple fuel injections into each combustion chamber during each power cycle. The '962 patent discloses that the controller determines whether to operate in the “normal fuel injection mode” or the “split fuel injection mode” based upon the temperature of the engine's coolant. Additionally, the '962 patent discloses that intake air temperature may also be a parameter that the controller uses in controlling the “split fuel injection mode.”
Although the '962 patent discloses controlling fuel delivery into the combustion chambers of the engine dependent upon intake air temperature in addition to engine coolant temperature, certain disadvantages persist. For example, the '962 patent provides no details regarding when or how the fuel injection control system would utilize intake air temperature as a parameter in controlling the “split fuel injection mode.” The engine controls may realize performance benefits from using the intake air temperature as a parameter in controlling fuel delivery to the combustion chambers only if the engine controls factor in the intake air temperature under appropriate circumstances and in appropriate manners.
The engine and operating methods of the present disclosure solve one or more of the problems set forth above.